US2069049A

US2069049A - Shock absorber

Info

Publication number: US2069049A
Application number: US693632A
Authority: US
Inventors: Saurer Curt
Original assignee: Firestone Tire and Rubber Co
Current assignee: Bridgestone Firestone Inc
Priority date: 1933-10-14
Filing date: 1933-10-14
Publication date: 1937-01-26
Anticipated expiration: 1954-01-26

Description

c. SAURER 2,069,049

SHOCK ABSORBER Filed oci. 14, 1935 2 Sheets-Sheet 1 Jan. 26, 1937.

. INVENTOR w E N R O w W A Y n- 7 c. SAURER SHOCK ABSORBER Filed Oct. 14, 1933 2 Sheets-Sheet 2V INVENTO R Gufl' Samver ATTO RNEYS Patented Jan. 26, 1937 UNITED STATES sHocK ABSORBER Curt Saurer, Akron, Ohio, assignor to The Firestone Tire & Rubber Company, Akron, Ohio,

a corporation of Ohio Application ctober 14, 1933, Serial No. 693,632

7 Claims.

This invention relates to so-called shock absorbers or vibration dampers such as are used, for example, on motor vehicles, and more especially it relates to shock absorbing devices em- .ploying both mechanical and hydraulic means for cushioning and abating the bound and rebound of the vehicle.

The chief objects of the invention are to check the bound and rebound of a vehicle with the same smoothness of operation; to provide the security and positive action of a mechanical shock absorber with the smoothness of operation of a hydraulic shock absorber; to provide, in a shock absorber improved means for cushioning the initial impact; and to provide a combination mechanical and hydraulic shock absorber wherein one of the shock absorbing elements cooperates with the other element in cushioning and damping shocks and vibration.

Of the accompanying drawings Figure 1 is an elevation of onei pmbodiment of the invention in its application to a motor vehicle; 7

Figure 2 is a section on the line 2-2 of Fig- Figure 3 is a section cit-the line 3-3 of Figure 2;

Figure 4 is an elevation of another embodiment of the invention applied to a motor vehicle;

Figure 5 is a section on the line 55 of Figure 4; and

Figure 6 is a section on the line B6 of Figure 5.

Referring to Figures 1 to -3 of the drawings,

the improved shock absorber, generally designated l0, comprises a housing composed of two mating, metallic shells of which the rear shell Illa is formed with suitable square bolt holes II, I I by which the structure may be mounted, as on the vehicle frame l2, by means of respective square-shouldered bolts I3, the heads of the latter being disposed interiorly of the housing. The margin of the shell Illa is formed with an ofiset flange l4 that is telescoped with the marginal 5 portion of the front shell "lb of the housing, said shells being permanently joined together as by welding to effect a fluid-tight juncture. In plan the housing is of general sector shape, having an arcuate lateral face that is concentric about an axis that is disposed within the housing structure.

At said axis the rear shell Illa is formed with an outwardly extending, cup-shaped formation I5 that constitutes a'journal bearing for one end 55 of a shaft I6 that is disposed interiorly of the housing. The said shaft extends through a suitable axial aperture in the front shell Illb, which aperture is formed with an annular flange 11 constituting a journal bearing for the front end of said shaft, the latter being peripherally grooved 5 at two points I8, 18 to accommodate suitable packing I9. Clamped upon the front end of the shaft I 6, exteriorly of the housing I0, is a lever arm 20, said lever arm being restrained against axial displacement by a washer 2|, and a bolt 10 22 that is threaded into the outer end of said shaft. The free end of lever arm 20 is pivotally connected to one end of'a link 23 that is pivotally connected at its other end to a fixture or bracket 24 that is mounted upon a spring-pad 15 of a vehicle axle 25. The arrangement is such that relative movement of the vehicle frame 12 and axle 25, due to bound or rebound, will be transmitted through the link 23 and lever arm 20 to the shaft 16 to cause angular movement or 20 rocking of the latter.

Permanently fixed upon the shaft l6, within the housing In, is a radial vane or piston 21 that is of general-rectangular shape and has its margins slightly spaced from the housing wall at 25 all points. The front, rear, and free marginal portions of the piston 21 are formed with respective flanges 28 that project laterally on both sides of the piston. In the normal position of the device the piston 21 is disposed vertically, 30 midway between the opposite sidewalls of the housing, as is most clearly shown in Figure 3.

Mounted within the housing I, in snug engagement with the opposite lateral faces of the piston 21 and the respective end walls of the 35 housing, are respective shock absorbing bodies or

cushions

29, 29 of resilient rubber composition. The said cushions are so arranged as to be subjected to compressive force alternatively as a the piston 21 is oscillated one way or the other 40 by rocking of the shaft I6, which force they yieldingly resist. The thickness of the cushions 29- is such that they are spaced from the front and rear walls of the housing,'the flanges 28 on the piston 21 serving to keep them in proper position. The top and bottom faces of the cushions preferably are somewhat concave as shown, the arrangement being such as to provide space for the displacement of the rubber of the cush ions, within the housing, when said cushions are placed under pressure.

The space within the housing l0 not otherwise occupied by the piston and cushions is filled with fluid 30 that preferably is non-freezing and noncorrosive so as not deleteriously to affect the 56 metal or rubber. Such a fluid may be a glycerin composition. The fluid is introduced into the housing after assembly through a duct 3| formed in the shaft [6, the bolt 22 being threaded into the outer end of the duct to provide a closure for the same.

In the operation of the device, oscillating movement of the piston in either direction is yieldingly resisted by the fluid and by the cushions. The space between the margins of the piston 21 and the housing wall is so small that the fluid passes to the opposite side of the piston in a small stream whereby the movement of the piston is retarded. This action is immediate upon any movement of the piston and serves to cushion the initial shock of bound or rebound of the vehicle, before either cushion 29 is appreciably deformed. The cushions supplement the retardirrg action of the fluid, and, because of their progressively increasing resistance to deformation, serve to slow down and, ultimately to limit the movement of the piston. The displacement of the rubber of cushions 29 when under pressure also serves to increase the pressure of the fluid on that side of the piston whereby the retarding ability of the fluid is amplified. Thepresence of the fluid in a shock absorber employing rubber as a cushioning means is advantageous in that the resistance of the fluid serves as a check against the expansive force of the deformed cushion, with the result that rebound is retarded and largely checked before the piston moves past center into engagement with the other cushion.

Referring now to Figures 4 to 6 of the drawings, there is shown therein an embodiment of the invention that operates on the same principles as the device hereinbefore described, but is of somewhat modified construction. The modified structure comprises a hollow, cylindrical housing 35 consisting of an upper shell 35a and a lower shell 35b, said shells being substantially of the same size and formed with respective

marginal flanges

36, 36 whereby they may be joined together in a fluid-tight seam as by the use of

bolts

31, 31.

The end wall of lower shell 35b is exteriorly 'formed with an apertured lug 38 by which the housing is pivotally mounted upon a shouldered bolt 39 carried by a bracket 49 that is mounted upon the frame member l2 of a vehicle. 5'- The upper shell 35 has its end wall axially apiertured and provided with a stufling box 4! for the piston rod 42 of a piston 43 within the housing, the diameter of the piston being somewhat smaller than the inside diameter of the housing to provide a narrow annular passage 44 about said transmitted through the link 23, lever arm 46,

and piston rod 42 to the piston 43 to cause axial .movement of the latter in its housing. Normally the piston is centrally positioned within the housing as is shown in Figure 5.

Mounted upon the piston rod 42 and extending from the top of the piston 43 to the upper end wall of the housing is a shock absorbing body or cushion 49 of resilient rubber composition. The periphery of the cushion 49 is formed with a series of spaced

circumferential ribs

50, 50 that define intervening channels 5!, 5!, the outer margins of the said ribs being spaced slightly from the inner face of the housing. Each of the ribs 50 is formed with a plurality of marginal notches or re-entrants-52, Figure 6, for a purpose presently to be described.

Interiorly the cushion 49 is formed with annular recesses or

hollows

53, 53 about the central aperture through which the piston rod 42 extends. Below the piston 43 is a cushion 54 that is similar in all respects to cushion 49 except that it has no axial aperture and the recesses 53 are omitted, said cushion 54 resting upon the bottom of the housing and abutting the bottom of the piston. The arrangement is such that the

cushions

49, 54 are substantially of equal resilience and exert a substantially equal resistance to deformation through axial movement of the piston. Space within the housing not occupied by the piston and cushions is filled with fluid, such as glycerin composition, that is admitted to the housing through a port 55 in the top thereof.

The

cushions

49, 54 and the fluid in the housing 35 supplement each other in resisting axial movement of the piston 43, and the deformation of said cushions modifies the normal action of the fluid in the same manner as in the other embodiment of the invention, whereby the shock absorbing character of the device is improved and the other objects set out in the foregoing statement of objects are achieved.

The invention may be otherwise modified without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. In a device of the character described, the r 2. In a device of the character described, the

journaled therein, an oscillating piston on said rock shaft having its margins spaced from the wall of the housing, blocks of resilient rubber engaging the respective lateral faces of the piston and opposite walls of the housing, a body of fluid occupying the remainder of the space within the housing, and means for passing fluid through the rock shaft and into the housing.

4. In a device of the character described, the combination of a closed cylindrical housing, a reciprocable axial piston rod extending thereinto, a piston on said piston rod spaced from the wall of the housing, respective blocks of resilient rubber engaging opposite sides of the piston and opposite endwalls of the housing, said rubber blocks being formed with radial flexible flanges extending substantially to the wall of the housing, said flanges being notched, and a body of liquid occupying the remainder of the space within the housing, said flanges being forced into yieldable sealing engagement with the wall of th housing by reason of the transverse expansion of the rubber blocks as the latter are alternately compressed by the piston.

5. In a shock absorber, the combination of a closed housing, a piston therein mounted inter-' mediate the ends of said housing and slightly spaced from the side walls thereof, said piston being movable within said housing, a liquid disposed in said housing at opposite sides of said piston, and a rubber member disposed in said "housing on each side of said piston, each of said be deformed by movement of said piston in a direction toward one end of said housing, the rubber member on one side of said piston increasing in cross-sectional area and the rubber member on the other side of said piston decreasing in cross-sectional area to displace the liquid from said end of the housing to the other end of said housing on the other side of said piston.

6. A shock absorber comprising a closed housing, a movable piston therein, said piston being spaced from said housing, a pair of deformable rubber members disposed in said housing between said piston and the respective ends of said housing, said deformable member being so proportioned within said housing as to provide a space between the member and said housing, a liquid medium disposed within said space entirely within said housing, said piston and housing being so constructed and arranged that said member may be deformed by movement of said piston as to displace said liquid from one end of said housing past said piston to the other end of said housing as said rubber member is transversely expanded by reason of longitudinal compression thereof by the piston.

7. A shock absorber comprising a closed housing, a movable piston within said housing, and a deformable rubber member interposed between said piston and an end of the housing, said deformable rubber member being provided with alternate ribs and grooves, a, liquid medium disposed within said grooves, whereby deformation of said rubber member by movement of said piston toward said end of the housing will cause displacement of the liquid medium within said grooves, said ribs constituting flexible packing rings for obstructing the flow of said liquid medium.

CURT SAURER.